1. Field of Invention
The present invention relates to apparatus used in the automated application of labels to objects. More particularly, the present invention relates to apparatus for applying labels to items prepared using automated packaging/labeling assembly lines. More particularly yet, the present intention relates to such apparatus that eliminates the need for assembly line shutdown for the loading of label stock whenever the existing label stock runs out. Even more particular yet, the present invention relates to such apparatus that incorporates multiple labeling heads in order to provide for the rapid introduction of a new label stock whenever the stock associated with a particular head becomes exhausted.
2. Discussion of Related Art
In modern assembly-line production of products for mass-market, an important stage in the process is product and packaging labeling. The use of automated labeling machines is common in today""s fast paced production and packaging lines. Typically, such machines are loaded with a roll or other configuration that contains a large number of the labels to be applied, one for each item as the item passes by or under the labeling machine. The labeling operation then typically consists of a portion of the labeling machine called the labeling xe2x80x9cheadxe2x80x9d making direct or indirect contact with each item so as to convey a single label to that item. Although there is a wide diversity of such machines reflecting the wide diversity of specific labeling needs, essentially all of these machines involve such a process and incorporate a component identifiable as a labeling head.
The rate at which items are processed on modern production/packaging assembly lines is overwhelming to the uninitiated observer, and represents one of the major reasons why so many mass production products can be delivered so inexpensively to the end consumer. One of the necessary consequences of this cost-reducing efficiency is the high cost associated with interruptions to the assembly line for even a short period of time. For those lines that have been developed to the point where mechanical breakdowns seldom occur, the major source of production shutdown is during the replenishment of supplies needed by the machinery processing the items. Specifically of interest to the present inventor is the delay that occurs when a load of labels runs out. Typically, when a roll of labels is exhausted, the assembly line has to be shut down while an attendant removes the spent label-container and replaces it with a new one containing labels. In addition to this production downtime, most industries require that a separate operator verify that the first operator reloaded the machine with the correct labels.
Recognizing the inefficiency associated with the need to change reels on automated labeling machines, a number of attempts have been made to circumvent the inefficiencies traditionally associated with the reel-changing. There are, for example, xe2x80x9cdouble unwindxe2x80x9d systems that provide an attendant the means, as an existing label reel is reaching its end, to attach the trailing end of that reel to the leading end of a new reel, thereby avoiding the need to stop the operation. However, because of the difficulty presented by the high speed of the operation, it is not a simple matter to operate the double-unwind system. Equally as troublesome is the high cost of labeling machines incorporating such provisions. Presently, these costs are on the order of $20,000 per machine. Added to this must be the cost of the attendant who must actively participate in the reel-transition operation. Although more complex machines that automate the reel-transition operation exist, those machines are far more expensive than their non-automated reel-transition counterparts.
In addition to the production stoppages necessitated by reloading label, all equipment is afflicted by occasional malfunctions. Labeling machines, where the malfunction primarily takes the form of jamming, are no exception. When a jam occurs, production is shut down until an operator can clear the jam and re-initiate the label feed. Neither the double-unwind machines requiring attendant participation nor the very expensive fully automated double-unwind machines address the problem of delays due to jamming and other production-halting mishaps with the labeling operation.
Therefore, what is needed is a labeling apparatus that eliminates or greatly reduces the delay associated with re-loading label stock at a relatively low cost. What is also needed is such apparatus that reduces the delay associated with labeling mis-feeds, jams, and other production-halting mishaps with the labeling operation.
The present invention greatly reduces the delay associated with reloading label stock, and it does this without imposing the costs inherent in the earlier attempts to solve this problem. Using the same concept that reduces the delay associated with reloading label stock, the present invention also eliminates the delays and costs traditionally associated with labeling mis-feeds and other malfunctions. The present invention accomplishes these functions by incorporating multiple independent label-feed mechanisms into standard industry production labelers. For definitiveness the discussion of the invention will often address only those embodiments that have just two such mechanisms; however, in general, the invention need not be so limited and is not.
Each of the independent label-feed mechanisms of the present invention will have a mounting means for a reel of label stock as well as a label head by which each label is serially transferred from the reel to the item to be labeled. Also included in each of the multiple mechanisms is the mechanical means for advancing the label reel down to and through the label head. The individual label-feed mechanisms are gang-loaded onto a slide frame and controlled in such a way that, when the label reel of one of the independent mechanisms reaches its final label, the entire operation is momentarily shut down. The ganged labeling mechanisms are then shifted sideways on the slide frame in such a manner that a xe2x80x9cloadedxe2x80x9d label head is now poised above the items to be labeled in exactly the same place as the now-empty-of-labels head had been just before the shutdown, i.e. the active labeling site. The total shutdown time for this operation can be as short as a few seconds. As part of the general monitoring of the production operation, an operator can, at his or her leisure or as part of a operator-dictated (as opposed to machine-dictated) schedule, without halting production, replace the depleted reel on the labeling mechanism that had been shifted out of active use with a full reel, thus enabling it to be shifted back into active use when the other mechanism in turn runs out of labels or becomes jammed.
By using this multiplicative approach, the apparatus of the present invention can minimize reel-transition time without the complexities of either type of xe2x80x9cdouble unwindxe2x80x9d machinery of the prior art. While it is true that the apparatus of the present invention cannot cut the label-restocking transition time below what the expensive automated double-winded machinery of the prior art can achieve, it does so at a lower cost. Moreover, by having a fully-charged label reel always ready to be introduced to the labeling operation at any time, the apparatus of the present invention is ideally suited to eliminate the down-time associated with label jamming. For example, the apparatus can be wired so as to detect a cessation of label reel rotation and to respond by shifting the apparatus, so that a non-jammed reel and associated mechanism is automatically moved into place as the jammed mechanism is moved away. Upon such an occasion, an operator can work with the jammed reel to free it up, without needing to stop production for the duration of this work. The apparatus can also be similarly wired so as to detect label head jams, and to similarly shift to the non-jammed labeling head so as to continue labeling with minimal interruption.
Although the present invention is not limited to any specific reel or head configuration or type of control, it is particularly suited to logic-based electronic control, where a single control unit governs the position of the gang of multiple mechanisms. This control then responds to any of a number of monitoring sensor alerts by shifting the array in one direction or the other. The monitoring sensors can be, but are not limited to, laser sensors, electronic sensors, optical sensors, or tactile sensors. The shifting can be accomplished by manual means, pneumatic means, an electric motor, or spring biases to name a few motive sources. In its simplest embodiments, the only choices are to shift the ganged labeling mechanisms one position to the right, or one position to the left. For example, a simple embodiment of the present invention will have two independent labeling mechanisms, a left independent labeling mechanism, and a right independent labeling mechanism. If the apparatus is currently labeling from the left independent labeling mechanism when an alert is received, the controller then shifts the ganged labeling mechanisms as to make the right independent labeling mechanism the current labeler. The control unit may also interact with other automated operations along the line itself, including conveyors, so that when the labeler is switching from one labeling mechanism to another, unlabeled product is not passing by. In another embodiment, the control unit may respond to sensing a labeling head jam or lack of labels by lighting an indicator light, sounding an alarm, or both. This indicator alerts the operator to manually slide the slidable frame into a position so as to place a fresh labeling mechanism over active labeling site.
It is to be noted that although types of automatic labeling apparatus that employ more than a single labeling head exist, all of those known to the present inventor that do so are directed to the function of applying more than a single label to a particular item. Furthermore, none of the known existing labelers are capable of shifting a labeling head into the same position that another labeling head had previously occupied.
Although for purposes of clarity, the present invention has been described with some specificity in this Summary and will be described with even more specificity in presenting its Preferred Embodiment, it is to be understood that from the disclosure contained herein, those skilled in the art of automated production equipment will be able to devise a great diversity of embodiments of the present invention, all of which inventor claims, as his invention.